This project is intended to continue our investigation of dynamic, life cycle decisions relating the timing of births, female labor supply (labor force participation) and non-market time allocation. Our aim is to generalize our previous sequential decision-making models and investigate, primarily using data from the Panel Study of Income Dynamics and the National Fertility Survey, 1970-1975, several important issues concerning the linkages between the timing and spacing of births and the time allocation decisions of married women in the United States. In particular we will examine: (1) The importance of economies of scale and the substitution between the mother's, father's and other inputs (such as relatives and institutional day care) in the "production" of child care and how these features of the care process affect the spacing of births and female time allocation over the life cycle. (2) The joint nature of the life cycle time allocation decisions of husbands and wives and the linkages of those decisions to the household's life cycle fertility decisions. (3) The importance of person-specific heterogeneity in fecundity upon contraceptive choice and its affect on the parents' ability to control the timing of births. In this investigation we will also examine the incidence and timing of voluntary sterilization of one or more of the parents. We will investigate how this decision is affected by parental wealth, the opportunity cost of his or her time and the level of the couple's fecundity. (4) Finally, we will investigate the importance of specifying structural formulations of life cycle fertility and time allocation models in fitting the data on actual birth histories.